Method of destroying refuse matter



Oct. 10, 1939'. H MORETON 2,175,301

METHOD OF DESTROYING REE USE MATTER Filed Au 19, 1935 1 I ,7W7Ld 47 Z].90

Patented Oct. 10, 1939 PATENT OFFICE METHOD OF DESTROYING REFUSE MATTERHenry H. Moreton,

Santa Monica, Calif.

Application August 19, 1935. Serial No. 36,934

8 Claims.

This invention is a method for destroying waste material such asgarbage, sewage, and the like.

Heretofore it has been proposed to incinerate garbage, sewage, etc., butowing to the high moisture content of such materials, the speed ofcombustion thereof is retarded, with the result that smoke, gases andobjectionable odors are discharged into the surrounding atmosphereduring the incinerating process.

One of the objects of the invention is to provide for complete andeconomical physical destruction of garbage by incineration, wherebypractically no residue is left, so that the possibility of either soilor water pollution is reduced to the absolute minimum. A further objectis to provide for complete incineration of garbage in such manner thatthe discharge of objectionable and offensive odors, smokes and gasesinto the surrounding atmosphere is prevented. A further object is toprovide a system of low installation cost and highly economic operation,capable of providing for initial dehydration of the garbage andsubsequent complete incineration in a continuous process. A furtherobject is to employ the caloric values inherent to the garbage beingtreated, to assist in the incineration of the material being treated,after its dehydration.

The invention will be hereinafter fully set forth and particularlypointed out in the claims.

In the accompanying drawing:

Figure 1 is a vertical elevation more or less diagrammatic in character,illustrating an apparatus constructed in accordance with the invention,certain parts being shown in section. Figure 2 is a detail sectionalView of a portion of one of the rotatable furnaces. Figure 3 is a sideelevation diagrammatically illustrating a modification. Figure 4 isanother modification.

Referring to the drawing, I designates a combined dehydrator andincinerator, which consists of a relatively long cylindrical chamber In,rotatively supported in a longitudinally inclined position, in a wellknown manner, by suitable bearings l l. Rotation of the cylindricalchamber may be effected by any suitable means, such as a gear l2engaging a gear-ring [3, which encircles the cylinder Ill. The higherend of said cylinder 10 projects into a receiving chamber it, throughthe top of which extends an inlet chute [6.

The open lower end of the cylindrical chamber In extends into a burnerbox 20, into which is projected one or more burners 2| for gas, oil, orthe like, the delivery ends of the burners being directed axially towardthe incinerator I, in such manner as to project the flame into the openlow r end of the latter. The burner casing rests upon a suitableplatform 22, onto which the chamber I0 deposits the material which isdischarged from the lower end thereof, said platform having a 5 chute 23which communicates with the interior of a mixing apparatus 24, operatedby a suitable motor 25. The mixing apparatus 24 may be of any suitableor desired construction, such as the common type of apparatus usuallyemployed for mixing concrete. It is preferred however, to provide themixer with a depending baflle 26, so as to trap the gases within themixing chamber, said gases being withdrawn by a suitable blower 21,which discharges the gases into the burner cham- 15 ber l4. The outerend of the receiving chamber l4 discharges into a stack S. The mixer isprovided with a discharge spout 28, leading from the upper portion ofthe mixing chamber, and which discharges onto a suitable conveyor 29, bywhich the material discharged from the mixer may be elevated to such aposition that the material will be discharged into the chute I6.

The garbage is placed in a suitable hopper G, which communicates througha suitable conduit 30 with the discharge chute 23, so that at a positionbelow the platform 22, the garbage will be intermingled with the heatedgranular material, as the latter travels from said platform to the mixer24. By this means a preliminary mixing of the garbage and granularmaterial is effected before they are delivered to the mixer 24 throughsaid chute 23.

In operation, assuming that the burners 2| are lighted and functioning,an initial charge of sand, or other similar non-absorbent inorganicgranular material, capable of withstanding high temperature withoutfusing, is fed to the conveyor 29 from a suitable source through aconduit 3!, said sand being elevated by the conveyor 29 and delivered tothe interior of the chamber I0 through the chute l6. As the chamber I0is rotated, the granular material is tumbled by a rotary motion andcaused to travel downwardly toward the lower end of the chamber so as tobe discharged through the chute 23 into the mixer 24. When the sandreaches the mixer 24, the apparatus has been primed. In this connection,it is to be understood that it is preferred to use good sharp silicasand, and a sufficient quantity must be initially introduced to insurecontinuing cycles of operation in a manner about to be described. As thesand travels through the chamber II), it will receive a high temperaturedue to the heat generated by the burners, which are directed toward thedownwardly flowing material in such manner as to impart the desiredtemperature to the sand, but the heat must be regulated so as to avoidfusing temperatures, because fusing of the sand particles would greatlyimpair the operation. Obviously, as the granular material moves out ofthe sphere of maximum heating influence of the burners 2 I, thetemperature thereof will begin to drop, and this drop of temperaturenaturally progresses during travel of said material through the chute 23and the mixer 24.

As the heated sand is discharged into the chute 23, the garbage is fedto said chute from the tank G. The garbage may be fed in any desiredform, but it is preferred to comminute it before placing it in the tankG. As the garbage leaves the conduit 30, it mingles with the travelingsand so that a preliminary mixture of sand and garbage is dischargedinto the mixer 24, where the constituents are more thoroughly mixed byagitation. The pressure created by the agitation within the mixer forcesthe finely mixed materials upwardly between the baffle plate 26 and theadjacent end of the mixer casing and out through the discharge spout 28to the conveyor 29. During travel of the granular material from theplatform 22 to the conveyor 29, the temperature of said material hasfallen to a considerable degree, but remains sufiiciently high toelevate the temperature of the garbage material to such a degree thatthe lighter, more volatile constituents of the latter are vaporized, andthe vapors are withdrawn by the pump 21. However, the temperature of thegranular material is not sufiiciently high to drive off all of themoisture, and as a consequence the particles of granular material, asthey are discharged into the conveyor have become surface-coated with}unvaporized moisture of the garbage. This moisture inherently carriesinorganic matter in solution.

The conveyor 29 elevates the final heated mixture of garbage andgranular material to such position that it may be discharged throughchute l6 into the chamber l0. As the mixture travels downwardly throughthe incinerator, it is subjected to a temperature which is sufficientlyhigh to completely dehydrate the surface coating of the granularmaterial while the mixture is travelling through the upper part of saidchamber l0. However, as the mixture travels downwardly through thechamber, the temperature maintained in the latter, i. e. an incineratingtemperature, is such that as dehydration is completed, the organicconstituents of the surface coatings, as well as the solid organicgarbage constituents which are intermixed with the granular material aresuccessively ignited and completely incinerated. Due to the interruptionof an annular bafile 32 placed within the cylinder II], a constantlymoving bed of fire back of the baffle is provided, with the result thatcomplete combustion takes place in this zone. It is to be understood,however, that the temperature within the heating zone is neversufficiently high to fuse the sand or other granular material. Thecombustion is so complete that there is practically no residual organicmatter left by the arbage, and the material which will be dischargedfrom the lower end of the chamber will be practically dried heated sand,which is immediately again deposited upon the platform 22 for transferinto the mixer 24. From this point, the cycles become continuous andautomatic, the sand and garbage being passed through the mixing anddehydrating, stages, new garbage being mixed with the sand as it flowsthrough the chute 23. As dehydration and incineration take place duringthe travel of the mixture through the chamber, steam is produced whichtends to reduce the odors, but if additional steam is required, it maybe supplied to the receiving chamber [4 through a pipe 33, leading froma source not shown. As the dehydration continues, combustible gases aregiven off, which are ignited by the heat within the cylinder, and thesame is true of the fumes delivered by the blower 21. These gases aid inthe combustion of dehydrated residual material. The products ofcombustion pass to the stack through box [4. Should it be necessary toadd fresh sand from time to time, it may be supplied through the pipe3|.

If desired, sewage may be mixed with the garbage as it is introducedinto the chute 23, leading to the mixer 24, as shown in Figure 4,wherein a tank 35 is connected by means of a pipe 36 with the conduit30, so that the sewage may be commingled with the garbage as the latteris entrained with the sand passing from the incinerator to the mixer. Inthis manner, sewage and garbage may be simultaneously destroyed.

In lieu of feeding the garbage and sand through a mixer, the garbage maybe directly fed to the chute l6, as illustrated in Figure 3, in whichthe garbage is supplied by means of a conveyor 36 leading to the chutel6 and joining with the delivery end of the conveyor 29. With thisarrangement, the garbage and sand are intermingled as they areintroduced into the chute l6, and a preliminary sand heating step isomitted.

The advantages of the invention will be readily apparent to thoseskilled in the art to which it belongs. An important advantage is thatthe non-absorbent granular material becomes surface-coated by suchmoisture content as remains with the garbage as it is introduced intothe incinerator, thereby creating a condition which makes it easy to socontrol the passage of the mixture through the chamber that evendehydration is effected. Therefore, after the apparatus is once put intooperation and the first cycle has been completed, less heat is requiredat the burner end than would otherwise be required, thereby reducing thechances of fusing the sand and yet insuring that the sand when it leavesthe incinerator will be in a condition for immediate mixing with moregarbage, so that a continuous hot sand cycle is provided. Anotheradvantage is that as the garbage and sand mixture enters the chamber In,it will first give off its moisture near the upper end of said chamberand later will be completely incinerated as it approaches the lower endof the chamber, the combustible gases given off during this stage beingcapable of developing sufiicient B. t. u. to very materially aid in thedestruction of garbage introduced during subsequent cycles. Anotheradvantage is that the mixture of sand and garbage travels in a generallongitudinal path, and that the burners project their flames in linesparallel with said path and at the terminal end thereof, so that thehottest zone in the incinerator is adjacent to its annular internalbafile.

Having thus explained the nature of the invention and described anoperative manner of constructing and using the same, although withoutattempting to set forth all of the forms in which it may be made, or allof the forms of its use, what is claimed is:

1. A method of destroying garbage comprising heating a refractorynon-absorbent granular material to a high temperature by causing it totravel through a heated zone maintained at a temperature below thefusing point of said material, recycling all of the non-absorbentmaterial through said heated zone while the material is still in itsheated state, mixing garbage with the hot non-absorbent material beforethe latter starts its recycling stage, and completely destroying thegarbage by causing the temperature within said heating zone toincinerate the garbage constituents while the mixture of sand andgarbage is traveling through said zone during said recycling stage, anddischarging the recycled garbage-free refractory material from saidheated zone in an unchanged granular state.

2. A method of destroying garbage comprising heating a refractorynon-absorbent granular material to a high temperature by causing it totravel through a heated zone maintained at a temperature below thefusing point of said material, recycling all of the non-absorbentmaterial through said heated zone while the material is still in itsheated state, mixing garbage with the hot non-absorbent material beforethe latter starts its recycling stage, causing the mixture to movethrough said heating zone in such manner as to increase the temperatureas the mass approaches the end of the recycling stage, causing thetemperature within said heating zone to incinerate the garbageconstituents of the mixture while said mixture is traveling through saidzone and discharging the recycled garbage-free refractory material fromsaid heated zone in an unchanged granular state.

3. A method of destroying garbage comprising heating a refractorynon-absorbent granular material to a high temperature by causing it totravel through a heated zone maintained at a temperature below thefusing point of said material, recycling all of the non-absorbentmaterial through said heated zone while the material is still in itsheated state, mixing garbage with the hot non-absorbent material beforethe latter starts its recycling stage, imparting a rotary tumblingmovement to the mixture during its travel through said heated zone,causing the temperature within said heating zone to incinerate thegarbage constituents of the mixture while said mixture is travellingthrough said zone and discharging the recycled garbage-free refractorymaterial from said heated zone in an unchanged granular state.

4. A method of destroying garbage consisting of mixing heated inorganicgranular material with garbage in such manner as to provide theparticles of granular material with surface coatings of unvaporizedgarbage moisture and to distribute garbage solids throughout thegranular material, dehydrating said coatings and subsequentlyincinerating the organic constituents of said coatings and of thedistributed garbage solids by subjecting the mixture to an incineratingtemperature while passing through a heated zone.

5. A method of destroying garbage consisting of mixing heated inorganicgranular material with garbage in such manner as to provide theparticles of granular material with surface coatings of unvaporizedgarbage moisture and to distribute garbage solids throughout thegranular material, conducting ofi any vapors which may be producedduring the mixing stage, dehydrating said coatings and subsequentlyincinerating the organic constituents of said coatings and of thedistributed garbage solids by subjecting the mixture to an incineratingtemperature while passing through a heated zone.

6. A method of destroying garbage consisting of mixing comminutedgarbage with a travelling mass of heated refractory granular material insuch manner as to provide the particles of granular material withsurface coatings of unvaporized garbage moisture and to distributegarbage solids throughout the granular material, causing the movingrefractory material and garbage mixed therewith to travel through aheated zone, and dehydrating said coatings and subsequently incineratingthe organic constituents of the coatings and the distributed garbagesolids by maintaining said zone at an incinerating temperature while thesand is conveying the garbage therethrough.

7. A method of destroying garbage comprising heating a refractorynon-absorbent granular material to a high temperature by causing it totravel through a heated zone maintained at a temperature below thefusing point of said material, recycling all of the non-absorbentmaterial through said heated zone while the material is still in itsheated state, mixing garbage with the hot non-absorbent material beforethe latter starts its recycling stage, dehydrating the garbageconstituents and then incinerating the residual constituents bysubjecting the mixture to an incinerating temperature while the mixtureis travelling through the heated zone during the recycling stage of therefractory material, and discharging the recycled garbage-freerefractory material from said heated zone in an approximately unchangedgranular state.

8. A method of destroying garbage comprising heating a refractorynon-absorbent granular material to a high temperature by causing it totravel through a heated zone maintained at a temperature below thefusing point of said material, recycling all of the non-absorbentmaterial through said heated zone while the material is still in itsheated state, mixing garbage with the hot non-absorbent material beforethe latter starts its recycling stage and in such manner as to providethe particles of granular material with surface coatings of unvaporizedgarbage moisture, and to distribute garbage solids throughout saidgranular material, dehydrating said coatings and subsequentlyincinerating the organic constituents of said coatings and of thedistributed garbage solids by subjecting the mixture to an incineratingtemperature while passing through said' heated zone during the recyclingstage of said refractory material, and discharging the recycledgarbage-free refractory material from the heated zone in an unchangedgranular state.

HENRY H. MORETON.

